Thread delivery and storage device

ABSTRACT

A thread delivery and, if necessary, storage device, preferably for textile machines and particularly for elastic threads to be used therewith. A coil member is provided to which a thread is continuously fed, moved axially, and then continuously removed tangentially. Rollers are arranged around the shaft of the coil member, each of said rollers being rotatable around its own axis and one thereof being driven. The axis of one of the rollers is pivotally mounted and normally slightly tilted, relative to the axis of the coil member both to effect the axial movement of the thread and to effect the desired control. The amount of thread wound on the coil member, and its axial location, determines the pivotal position of the tilted roller, and the passing of said tilted roller in one direction or the other of a given tilted position operates a switch or other control means to bring about the desired control over the operation of a driving motor.

United States Patent Rosen 1 Aug. 29, 1972 [54] THREAD DELIVERY AND STORAGE 3,209,558 10/1965 Cargill ..242/47.11 X DEVICE 3,419,225 12/1968 Rosen ..242/47.12 [72] Inventor: Karl sac Joel Rosen, Vina Haga 3,490,710 1 1970 Muhlhausler ..242/47.01

Ulricehamn Sweden Primary ExaminerSta.nley N. Gilreath [22] Filed: April 9, 1970 Att0rneyWoodhams, Blanchard and Flynn [21] Appl. No.: 26,913 [57] ABSTRACT A thread delivery and, if necessary, storage device, [30] Forelgn Apphcauon Pnomy Data preferably for textile machines and particularly for April 11, 1969 Sweden ..5107/69 elastic threads to be used therewith A Coil member is J 9 1970 Germany p 20 0 4 provided to which a thread is continuously fed, moved axially, and then continuously removed tangentially. 52 US. Cl. ..242/47.12 Rollers are arranged around the shaft of the coil 51 Int. Cl. ..B65h 51/26 member, each of Said rollers being rotatable around its [58] Field of Search..242/47.12, 47.13, 47.01, 47.08, axis and one thereof bfiing driven- The axis of one 242/4709 47 47 1. /132 Of the rollers is pivotally mounted and normally slightly tilted, relative to the axis of the coil member R both to effect the axial movement of the thread and to [56] eferences Cl effect the desired control. The amount of thread UNITED STATES PATENTS wound on the coil member, and its axial location, determines the pivotal position of the tilted roller, and 1349983 3,1932 Junkers the passing of said tilted roller in one direction or the Weaver other of a given position operates a Switch or 532:: et a1 other control means to bring about the desired control o the rati of dr'vin moto 2,936,877 5/1960 Adams et al ..242/4709 vet ope a g r 3,099,143 7/1963 Sinclair ..66/ 132 12 Claims, 9 Drawing Figures Patented Aug. 29, 1972 5 Sheets-Sheet 1 Patented Aug. 29; 1972 Y 3,687,384

5 Sheets-Sheet 2 INVENTQR Mil A546 (/45! PdJf/V Patented Aug. 29, 1972 5 Sheets-Sheet 5 INVENTOR K4,?! we am my! v Patented Aug. 29, 1972 3,687,384

5 Sheets-Sheet 4 iMzaM/% THREAD DELIVERY AND STORAGE DEVICE The invention relates to a thread delivery and, if necessary, storage apparatus, preferably for textile machines and in particular for elastic threads, comprising a coil device to which the thread can be fed tangentially and on which the tread windings can be transported axially, which has a stationary support part and two or more rollers held therein and arranged around the center shaft of the coil member. Said rollers are each rotatable about their own axes, whereby at least one of the rollers is drivable and the axis of at least one of the rollers is tilted tangentially relative to the center shaft. The apparatus further comprises a drive means for the roller or the rollers and a control means influencing the drive means depending on the amount of the stored thread.

Such apparatuses are used to withdraw thread, yarn or the like from a storage spool and to feed it to a processing machine at as constant a tension as possible. During operation, the coil device must be able to receive and discharge yarn at the same time. It is thereby necessary that during the winding operation the thread windings are moved continuously and as evenly as possible in an axial direction so that the withdrawal of the thread is not prevented by windings lying thereon. The number of the thread windings looped around the coil device must be limited to both sides by the control apparatus. A minimum amount must be supplied to assure the smooth operation of the processing machine and yet the supply should be held within a maximum amount which if exceeded could lead to a sliding off of the windings or to the positioning of same thereof on top of others. A

A thread delivery apparatus is already known (British Pat. No. 352,454) which is connected between a thread working device and a winding device which forms a storage spool of the working thread, namely for balancing the different speeds with which the thread leaves the working device and the speed with which it is wound. This known thread delivery apparatus has two rollers which are driven by a common drive for the entire apparatus which consists of the mentioned and further auxiliary devices and operates constantly. One of the rollers is tilted with respect to the center axis of the coil device in such a manner that it affects the axial feed of the thread windings. The withdrawal of the thread is done overhead. The thread is thereby guided through an eyelet of an arm arranged radially with respect to the coil device at its lower end. This arm is supported by means of a slip clutch on a shaft which is driven concentrically with the coil member. Depending on the relation between the withdrawal speed of the thread from the coil device and the feed speed, said slip clutch is engaged or disengaged so that the arm moves either in the same direction as the rollers or opposite thereto. The number of the thread windings formed on the coil device increases or decreases accordingly. Nevertheless, this is an expensive, uncertain, and potentially trouble-creating device by which the tension of the withdrawn thread is to be maintained constant. The exceeding of a maximum number of windings or the excessively rapid sliding of the windings downwardly is intended to be prevented by a control apparatus which has a lever pivotably arranged between the rollers in the lower zone of the coil device.

In its normal position one arm of this lever projects in the form of a downwardly inclined surface from the ideal contour of the coil device, said contour being determined by the rollers. When the thread windings during their axial movement downwardly reach said inclined surface, they effect a movement of the lever through which same contact a switching element. The operation of the switching element turns on a magnetic spool which then attracts a magnet core. The movement of the magnet core causes an elevation adjustment of the driving belt of the drive apparatus relative to the conical drive wheels for the thread delivery device in such a manner that the rollers rotate slower until the number of windings is reduced at which time a spring presses the driving belt back into the original position. This device utilizes components which in both structure and in operation are susceptible to trouble and also cannot prevent the sliding off of windings if this happens quickly because the projecting lever arm which stops the movement is pressed inwardly, thus out of the way, by the windings. Further, it is not possible to stop this known thread delivery device by means of th control apparatus.

The purpose of the invention is to produce a thread delivery and, if necessary, storage apparatus of the type described above which in its method of operation can 'be adjusted to any thread processing and working devices which are arranged in front or after said device, which can be used in many ways and which has a simple, economical and sturdy structure.

To attain this purpose the invention provides that control means is connected to one of the rollers and said roller is swingably arranged at least radially to the center shaft of the storage member in such a manner that its displacement is caused by the thread windings then in place.

In the thread delivery and, if necessary, storage apparatus of the invention, the swingable roller itself forms the switching element. The thread windings which move from the introduction zone of the coil device axially into the withdrawal zone pull the free end of the swingable roller continuously toward the center shaft. The other end of the swingable roller which end is near the pivot point moves automatically in the opposite direction and can, when a certain deflection is reached, act on a part of the control means, for example a contact. The slow swinging movement of the roller can thereby be used from a certain point on to a stepwise changing of the roller speed and/or for turning off the drive for the rollers as long as said drive works independent from the devices which are connected before or after the device. The direct reciprocal action between the swingable roller and the thread windings moving axially on said roller permits a very sensitive, thus exact, control of the apparatus depending on the number of windings and the thread tension. Since an additional switching element, as illustrated by the lever in the above-described known device, is not required, the structure of the apparatus is simpler, more sturdy and less susceptible to trouble.

The swingable roller has advantageously associated therewith a guide apparatus which during a radial swinging of said roller adjusts at least one of the rollers of the coil member in such a manner that the influence of the radial swinging movement on the axial feed of the thread windings is at least balanced. A radial movement of the swingable roller, regardless of its magnitude, effects a change of the ideal size of the coil member determined by the rollers which provide a quicker axial feeding of the windings. The balance effected by the guide apparatus permits the swingable roller to be easily moveable in a favorable manner. The radial swinging movement can be influenced by windings at an early point in the procedure without the axial transport of the thread being accelerated even though during this stage the swingable roller is not yet in contact with the control apparatus. This particularly advantageous if the swingable roller is provided only for switching on and off of the drive means through the control apparatus, thus must cover a relatively large path of swing until it reaches the contact. This guide apparatus can be constructed and act in various manners.

At least one of the rollers of the coil device can be adjusted by the guide apparatus to a tangential inclination acting against the axial feed of the thread windings. This inclination is contrary to the inclination provided in the coil member at one or more rollers, which latter inclination effects the axial feed of the thread windings downwardly so that the thread windings receive a smaller angle of inclination.

In a preferred embodiment in which the swingable roller is swingably suspended at its end lying in the zone of the thread feed and is arranged radially inwardly swingably in the zone of its end facing the thread runoff, the guide apparatus for forcing a tangential inclination of the swingable roller consists of a recess in a plate of the support part, said plate supporting the rollers, which recess is penetrated by an axial extension projection of the swingable roller. The recess is thereby arranged at an angle to the tangent of the ideal contour of the coil device in such a manner that the free end of the roller moves at the radial movement forced by the thread windings simultaneously in tangential direction inwardly. Thus the balance of the swinging movement is achieved in a simple manner exactly corresponding to the radial movement for which an angle of 45 has proven to be advantageous in the preferred embodiment. The pivot point of the swingable roller is advantageously arranged inside of said roller. The path of swing of the end connected to the control means is in this manner enlarged and offers more possibilities of adjustment for the control means, among others for the number of windings at which the drive is turned off.

In other embodiments of the thread storage and delivery apparatus of the invention, at least one of the rollers can be radially offset by the guide apparatus during the radial swinging of the swingable roller in such a manner that the size of the coil device remains constant. The guide apparatus can in this case consist of a simply constructed mechanical coupling device between the swingable and the offset table roller.

In an advantageous further development of the thread delivery and storage apparatus of the invention, the coil device has a bulge or the like at the withdrawal end of the thread, said bulge being driven in the same direction of rotation as the rollers and guiding the withdrawal end of the thread by means of friction around the coil member. This bulge thus causes the axial transport of the thread windings to be accomplished evenly, usually independently from the withdrawal speed and assures therewith the satisfactory functioning of the swingable roller as a switching element. It has advantageously at the withdrawal end of the thread a brake ring which influences the withdrawal speed of the thread. The thread is thus fed with a constant tension to a winding-up or processing apparatus which is arranged following the device of the invention. The peripheral speed of the bulge must at all times be greater than the speed of the rollers forming the coil member. A loop formation in the thread is also thereby avoided.

One exemplary embodiment of the invention is illustrated in the drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of the thread delivery and storage device of the invention;

FIG. 2 is a side-elevationa] view of a schematized roller arrangement of the device according to FIG. 1;

FIG. 3 is a schematized front view of the upper roller ends;

FIG. 4 is a schematized side view of two rollers which are diametrically arranged from one another in the device;

FIG. 5 is a schematized view of the rollers and of a feed device seen from below;

FIG. 6 is a schematic view of a part of a drive apparatus for the device;

FIG. 7 is a longitudinal cross-sectional view of a control apparatus of the device and a roller cooperating with same;

FIG. 8 illustrates the control apparatus and the roller according to FIG. 7 in a different operating position; and

FIG. 9 is a detailed view of the device from below.

The illustrated thread delivery and storage device has a coil device 40, through the center shaft 1 of which is taken the longitudinal cross section illustrated in FIG. 1. Four rollers 2 to 5, each rotatable about its own axis, are arranged concentrically around the center shaft 1. The roller 4 is not illustrated in cross section in FIG. 1. The rollers are supported at one end in a frame 6 constructed as a mounting plate and at the other end in a support 7, whereby the support plate 7 is connected to the frame 6 by means of a central pipe 8. The frame 6 and the support plate 7 together form a stationary support part for the axes of the rollers.

The roller 2 is freely rotatably supported while the rollers 3 to 5 are drivable. In driven condition they permit a thread 9 fed in the zone of the frame 6 to move around the coil device 40 and wind the thread as windings thereon. The end of the rollers 2 to 5 which is near the frame 6 is thus the thread feeding end. motor 10 which drives a gear 11 is arranged in the frame 6 as a drive mechanism for the rollers 3 to 5. The gear 11 drives a gear 12 on the shaft of the roller 3 which is in meshing engagement with a gear 13 which in turn is freely supported on the center shaft 1. This gear 13 drives on one side gears 14 and 15 which are rigidly connected to the shafts of the rollers 4 or 5. The rollers 3 to 5 are thus moved in the same direction of rotation. A schematic illustration of this drive apparatus without the motor 10 is shown in FIG. 6.

The shafts of all rollers 2 to 5 are tilted tangentially relative to the center shaft 1. This inclination can be seen particularly from the schematic illustration in FIGS. 3 and 4. The inclination lies in the magnitude of approximately 1. This slight inclination does not cause a problem in the transfer of motion between the gears 11 to 13, however, it is sufficient to effect a feed movement of the thread windings during winding up in the axial direction of the coil device.

A control switch 16 which cooperates with the roller 2 is associated with the drive motor 10. This arrangement is again shown in two operating positions in FIGS. 7 and 8. The control switch 16 effects a turning on and off of the motor and therewith through the driven rollers 3 to 5 the moving or stopping of the thread windings 17 spooled onto the coil device 40, depending on their amounts. The roller 2 is rotatably supported on a nonrotatable shaft 18 by means of ball bearings 19 and 20. The shaft 18 is pivotably supported around a pivot point 21 in a holding plate 22 of the frame 6. The end of the shaft 18 remote from the pivot point 21 is movably guided in a slot 23 of the support plate 7 as can be seen from the schematic illustration of FIG. 9. The slot 23 extends approximately at 45 to the tangent of the circular support plate 7. The end of the shaft 18 close to the pivot point 21 is rigidly connected to an arm 32, the free end of which abuts a microcontact 39 of the control switch 16 and is connected to a tension spring 24. Both the tension force of spring 24 and also a spring (not illustrated) which presses the contact 39 against the arm 32 in the control switch 16 act thereby onto this end of the arm 32. When the number of the thread windings increases whereby these move at the same time axially into the lower zone, namely to the free end of the roller 2, the thread windings exert a tension force directed radially to the center shaft 1 onto the roller 2. Through this, the roller 2 moves continuously into the position illustrated in FIG. 8. The free end of the shaft 18 is thereby guided in addition to the radial movement tangentially in the slot 23. The free end of the arm 32 overcomes in the end position (FIG. 8) the load produced both by the spring 24 and also by the microcontact and brings same into a switch operating position. The motor 10 is thus turned off, and the thread windings 17 are stopped. The time of this switching process, namely the amount of the thread to be wound up, is controllable through the tension of the spring 24. The slot 23 in the support plate 7 is arranged in such a manner that the tangential movement of the roller 2 maintains the circumference of the coil device substantially constant so as to counterbalance any increase in the axial acceleration of the thread windings which is caused by the radial inward swinging.

As can be seen from FIGS. 7 and 8, the pivot point 21 of the roller 2 is arranged within the roller so that the end of said roller cooperating with the control switch has a greater clearance.

The thread is pulled downwardly from the coil device by a textile machine (not illustrated). The withdrawal end of the thread identified with 25 in FIG. 5, runs from the rollers 2 to 5 over a rotating disk 26 which is provided with a bulge 27 and a brake ring 28 arranged thereon. The brake ring 28 has arranged thereon annular fingers which are positioned in a downwardly inclined manner. The thickness and/or closeness of the fingers determines the magnitude of the friction coefficient. The disk 26 is rotatably supported on the pipe 8 by means of ball bearings 29. The disk is driven through the center shaft 1 by a gear 30 which is rigidly mounted to its upper end. The gear 30 is in meshing engagement with the gear 11 of the motor 10 as can be seen from the schematic drive illustration of FIG. 6. The disk 26 is rotated therewith in the same direction as the rollers 2 to 5 and at a speed which due to the arrangement of the gears is brought into a predetermined relationship to the winding-up speed of the thread.

As can be seen from FIG. 1, the roller 4 has a conical flange 31 at the thread feed end, through which flange the first winding of the thread 9 is guided longer in axial direction than is effected by the tiltingof the roller axes.

At the withdrawal end of the coil device the rollers 2 to 5 have conically enlarged sections 33 which press thread windings running thereonto against one another and thus cause a tighter winding.

A square 34 with a holding screw 35 is arranged on the frame 6 for mounting onto a processing machine, for example a knitting machine. Furthermore the frame 6 has an arm 36 which carries a thread guide 37 at its end. The thread guide 37 is in alignment with the center shaft 1. In a part of the frame, which part is identified with 38 in FIG. 1, a thread tester (not illustrated) of a. known type is arranged. The thread 9 is guided past said tester before winding thereof; The thread tester stops the subsequent processing machine when errors in the thread are discovered.

The device of the invention is to be used primarily for threads or yarns, like nonbraided lycra or rubber, which are particularly difficult to work. However, it can also be used for more or less elastic synthetic yarns as, for example, crimplene.

The invention is not limited to the exemplary em- 1 bodiment. The number of rollers can be varied from two on up. Any desired number thereof, from one on up, can, adjusted to the respective operating conditions, be drivable and the remaining ones can be arranged to be freely rotatable. In the exemplary embodiment, the axes of all rollers are tilted. Depending on the quality of the thread, the tilting of one axis can be sufficient for the axial forwarding of the thread windings.

- The elements, which during displacement of the roller co-operating with the-control switch act on said control switch can be replaced by suitable other components, for example by a compound lever arrangement. It is also possible to permit the end of the respective roller axis close to the pivot point to act directly onto a contact.

The guide apparatus for balancing the radial movement of the pivotable roller can consist of a rigid, leverlike or gearlike coupling element or several such elements which during a radial swinging of the swingtable roller tangentially adjust or move one or several of the remaining rollers in such a manner that the size of the coil device remains unchanged. It is also possible to effect the balancing adjustment of another than the swingable roller through the control switch or apparatus loaded by the swinging of the adjustable roller.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. In a thread delivery and, if necessary, storage apparatus, preferably for textile machines and in particular for elastic thread, said apparatus having coil means defining a longitudinally extending axis and to which a thread can be fed tangentially and on which thread windings can be transported axially, said coil means including a stationary support member and a plurality of rollers mounted thereon for rotation about their respective axes, the axes of said rollers extending in a direction approximately parallel with the longitudinal axis of said coil means, at least one of the rollers being drivable and the axis of at least one of the rollers being tilted tangentially relative to said longitudinal axis, drive means operatively interconnected to the drivable roller for driving same, and control means for controlling said drive means in dependence upon the amount of thread stored on the coil means, the improvement comprising mounting means coacting with one of said rollers for permitting swinging movement of said roller in a direction at least radially relative to the longitudinal axis of said coil means, swingable movement of said swingable roller being caused by the thread windings wound on the coil means, and said control means being operatively connected to said swingable roller, whereby swinging movement of said swingable roller controls said control means.

2. An apparatus according to claim 1, further including guide means associated with said swingable roller for controlling the swinging movement thereof for causing a variation in the tangential position of one of said rollers in response to radial movement of said swingable roller for balancing the axial feed of the thread winding along the coil means.

3. An apparatus according to claim 2, wherein said guide means causes a tangential displacement of said one roller relative to the longitudinal axis of said coil means in response to radial displacement of said swingable roller.

4. An apparatus according to claim 2, wherein said guide means causes both a radial and a tangential displacement of said swingable roller for balancing the effect of movement of said swingable roller on the axial feed of the thread windings.

5. An apparatus according to claim 1, wherein the thread is tangentially fed onto the coil means adjacent one axial end thereof and is withdrawn from'the coil means adjacent the other axial end thereof, one end of said swingable roller being swingably supported by said mounting means adjacent said one end of said coil means, and the other end of said swingable roller being disposed adjacent the other end of said coil means and being freely radially swingable.

6. An apparatus according to claim 5, further including guide means associated with the other end of said swingable roller for simultaneously causing both radial and tangential displacement thereof, said guide means including a projection secured to one of said swingable roller and said support member, said guide means further including an elongated recess formed in the other of said swingable roller and said support member.

7. An apparatus according to claim 3, wherein said guide means causes the circumference of said coil means to remain substantially constant when said swingable roller is radially displaced.

8. An apparatus according to claim 1, wherein said coil means includes a disk member disposed adjacent the withdrawal end of said coil means, said disk m mber havin adiall ro'ectin b l e, and said drive means b ei g driviri gfy cionnetetl %0 said disk member for causing rotation thereof in the same direction as said rollers, whereby said disk member guides the withdrawal end of the thread by means of friction around the coil means.

9. An apparatus according to claim 8, further including a brake ring disposed adjacent the withdrawal end of said coil means for controlling the withdrawal speed of the thread from the coil means.

10. An apparatus according to claim 9, wherein the brake ring is arranged on and rotates with the disk member.

1 1. An apparatus according to claim 10, wherein said drive means is interconnected to said disk member for causing rotation thereof at a speed whereby the peripheral speed of the brake ring is greater than the peripheral speed of the rollers.

12. An apparatus according to claim 1, wherein said coil means includes a pair of spaced, stationary support members fixedly interconnected by a central shaft extending therebetween, said central shaft defining the longitudinal axis of said coil means, and said plurality of rollers being substantially uniformly spaced around said shaft and extending between and being rotatably supported on said first and second support members, one end of said swingable roller being pivotally connected adjacent one support member, the other end of said swingable roller as disposed adjacent the other support member being freely radially swingable relative to said central shaft, and said control means including switch means operatively interconnected to said one end of said swingable roller for actuation thereby in response to swinging movement of said swingable roller. 

1. In a thread delivery and, if necessary, storage apparatus, preferably for textile machines and in particular for elastic thread, said apparatus having coil means defining a longitudinally extending axis and to which a thread can be fed tangentially and on which thread windings can be transported axially, said coil means including a stationary support member and a plurality of rollers mounted thereon for rotation about their respective axes, the axes of said rollers extending in a direction approximately parallel with the longitudinal axis of said coil means, at least one of the rollers being drivable and the axis of at least one of the rollers being tilted tangentially relative to said longitudinal axis, drive means operatively interconnected to the drivable roller for driving same, and control means for controlling said drive means in dependence upon the amount of thread stored on the coil means, the improvement comprising mounting means coacting with one of said rollers for permitting swinging movement of said roller in a direction at least radially relative to the longitudinal axis of said coil means, swingable movement of said swingable roller being caused by the thread windings wound on the coil means, and said control means being operatively connected to said swingable roller, whereby swinging movement of said swingable roller controls said control means.
 2. An apparatus according to claim 1, further including guide means associated with said swingable roller for controlling the swinging movement thereof for causing a variation in the tangential position of one of said rollers in response to radial movement of said swingable roller for balancing the axial feed of the thread winding along the coil means.
 3. An apparatus according to claim 2, wherein said guide means causes a tangential displacement of said one roller relative to the longitudinal axis of said coil means in response to radial displacement of said swingable roller.
 4. An apparatus according to claim 2, wherein said guide means causes both a radial and a tangential displAcement of said swingable roller for balancing the effect of movement of said swingable roller on the axial feed of the thread windings.
 5. An apparatus according to claim 1, wherein the thread is tangentially fed onto the coil means adjacent one axial end thereof and is withdrawn from the coil means adjacent the other axial end thereof, one end of said swingable roller being swingably supported by said mounting means adjacent said one end of said coil means, and the other end of said swingable roller being disposed adjacent the other end of said coil means and being freely radially swingable.
 6. An apparatus according to claim 5, further including guide means associated with the other end of said swingable roller for simultaneously causing both radial and tangential displacement thereof, said guide means including a projection secured to one of said swingable roller and said support member, said guide means further including an elongated recess formed in the other of said swingable roller and said support member.
 7. An apparatus according to claim 3, wherein said guide means causes the circumference of said coil means to remain substantially constant when said swingable roller is radially displaced.
 8. An apparatus according to claim 1, wherein said coil means includes a disk member disposed adjacent the withdrawal end of said coil means, said disk member having a radially projecting bulge, and said drive means being drivingly connected to said disk member for causing rotation thereof in the same direction as said rollers, whereby said disk member guides the withdrawal end of the thread by means of friction around the coil means.
 9. An apparatus according to claim 8, further including a brake ring disposed adjacent the withdrawal end of said coil means for controlling the withdrawal speed of the thread from the coil means.
 10. An apparatus according to claim 9, wherein the brake ring is arranged on and rotates with the disk member.
 11. An apparatus according to claim 10, wherein said drive means is interconnected to said disk member for causing rotation thereof at a speed whereby the peripheral speed of the brake ring is greater than the peripheral speed of the rollers.
 12. An apparatus according to claim 1, wherein said coil means includes a pair of spaced, stationary support members fixedly interconnected by a central shaft extending therebetween, said central shaft defining the longitudinal axis of said coil means, and said plurality of rollers being substantially uniformly spaced around said shaft and extending between and being rotatably supported on said first and second support members, one end of said swingable roller being pivotally connected adjacent one support member, the other end of said swingable roller as disposed adjacent the other support member being freely radially swingable relative to said central shaft, and said control means including switch means operatively interconnected to said one end of said swingable roller for actuation thereby in response to swinging movement of said swingable roller. 